#include <bits/c++config.h>
#endif
-#include <string>
-#include <cstring>
-#include <cassert>
#include <algorithm>
+#include <cassert>
+#include <cstring>
+#include <string>
+#include <utility>
-#include <folly/Traits.h>
-#include <folly/Malloc.h>
#include <folly/Hash.h>
-#include <folly/ScopeGuard.h>
+#include <folly/Malloc.h>
+#include <folly/Traits.h>
#if FOLLY_HAVE_DEPRECATED_ASSOC
#ifdef _GLIBCXX_SYMVER
namespace fbstring_detail {
template <class InIt, class OutIt>
-inline
-OutIt copy_n(InIt b,
- typename std::iterator_traits<InIt>::difference_type n,
- OutIt d) {
+inline std::pair<InIt, OutIt> copy_n(
+ InIt b,
+ typename std::iterator_traits<InIt>::difference_type n,
+ OutIt d) {
for (; n != 0; --n, ++b, ++d) {
*d = *b;
}
- return d;
+ return std::make_pair(b, d);
}
template <class Pod, class T>
-inline void pod_fill(Pod* b, Pod* e, T c) {
+inline void podFill(Pod* b, Pod* e, T c) {
assert(b && e && b <= e);
/*static*/ if (sizeof(T) == 1) {
memset(b, c, e - b);
* adaptation outside).
*/
template <class Pod>
-inline void pod_copy(const Pod* b, const Pod* e, Pod* d) {
+inline void podCopy(const Pod* b, const Pod* e, Pod* d) {
assert(e >= b);
assert(d >= e || d + (e - b) <= b);
memcpy(d, b, (e - b) * sizeof(Pod));
* some asserts
*/
template <class Pod>
-inline void pod_move(const Pod* b, const Pod* e, Pod* d) {
+inline void podMove(const Pod* b, const Pod* e, Pod* d) {
assert(e >= b);
memmove(d, b, (e - b) * sizeof(*b));
}
+// always inline
+#if defined(__GNUC__) // Clang also defines __GNUC__
+# define FBSTRING_ALWAYS_INLINE inline __attribute__((__always_inline__))
+#elif defined(_MSC_VER)
+# define FBSTRING_ALWAYS_INLINE __forceinline
+#else
+# define FBSTRING_ALWAYS_INLINE inline
+#endif
+
+[[noreturn]] FBSTRING_ALWAYS_INLINE void assume_unreachable() {
+#if defined(__GNUC__) // Clang also defines __GNUC__
+ __builtin_unreachable();
+#elif defined(_MSC_VER)
+ __assume(0);
+#else
+ // Well, it's better than nothing.
+ std::abort();
+#endif
+}
+
} // namespace fbstring_detail
/**
// e.g. reference-counted implementation to fork the data. The
// pointer is guaranteed to be valid until the next call to a
// non-const member function.
- Char * mutable_data();
+ Char* mutableData();
// Returns a pointer to string's buffer and guarantees that a
// readable '\0' lies right after the buffer. The pointer is
// guaranteed to be valid until the next call to a non-const member
// If expGrowth is true, exponential growth is guaranteed.
// It is not guaranteed not to reallocate even if size() + delta <
// capacity(), so all references to the buffer are invalidated.
- Char* expand_noinit(size_t delta, bool expGrowth);
+ Char* expandNoinit(size_t delta, bool expGrowth);
// Expands the string by one character and sets the last character
// to c.
void push_back(Char c);
fbstring_core(const fbstring_core & rhs) {
assert(&rhs != this);
- // Simplest case first: small strings are bitblitted
- if (rhs.category() == Category::isSmall) {
- static_assert(offsetof(MediumLarge, data_) == 0,
- "fbstring layout failure");
- static_assert(offsetof(MediumLarge, size_) == sizeof(ml_.data_),
- "fbstring layout failure");
- static_assert(offsetof(MediumLarge, capacity_) == 2 * sizeof(ml_.data_),
- "fbstring layout failure");
- // Just write the whole thing, don't look at details. In
- // particular we need to copy capacity anyway because we want
- // to set the size (don't forget that the last character,
- // which stores a short string's length, is shared with the
- // ml_.capacity field).
- ml_ = rhs.ml_;
- assert(category() == Category::isSmall && this->size() == rhs.size());
- } else if (rhs.category() == Category::isLarge) {
- // Large strings are just refcounted
- ml_ = rhs.ml_;
- RefCounted::incrementRefs(ml_.data_);
- assert(category() == Category::isLarge && size() == rhs.size());
- } else {
- // Medium strings are copied eagerly. Don't forget to allocate
- // one extra Char for the null terminator.
- auto const allocSize =
- goodMallocSize((1 + rhs.ml_.size_) * sizeof(Char));
- ml_.data_ = static_cast<Char*>(checkedMalloc(allocSize));
- // Also copies terminator.
- fbstring_detail::pod_copy(rhs.ml_.data_,
- rhs.ml_.data_ + rhs.ml_.size_ + 1,
- ml_.data_);
- ml_.size_ = rhs.ml_.size_;
- ml_.setCapacity(allocSize / sizeof(Char) - 1, Category::isMedium);
- assert(category() == Category::isMedium);
+ switch (rhs.category()) {
+ case Category::isSmall:
+ copySmall(rhs);
+ break;
+ case Category::isMedium:
+ copyMedium(rhs);
+ break;
+ case Category::isLarge:
+ copyLarge(rhs);
+ break;
+ default:
+ fbstring_detail::assume_unreachable();
}
assert(size() == rhs.size());
assert(memcmp(data(), rhs.data(), size() * sizeof(Char)) == 0);
fbstring_core(const Char *const data,
const size_t size,
bool disableSSO = FBSTRING_DISABLE_SSO) {
+ if (!disableSSO && size <= maxSmallSize) {
+ initSmall(data, size);
+ } else if (size <= maxMediumSize) {
+ initMedium(data, size);
+ } else {
+ initLarge(data, size);
+ }
#ifndef NDEBUG
#ifndef _LIBSTDCXX_FBSTRING
- SCOPE_EXIT {
- assert(this->size() == size);
- assert(size == 0 || memcmp(this->data(), data, size * sizeof(Char)) == 0);
- };
+ assert(this->size() == size);
+ assert(size == 0 || memcmp(this->data(), data, size * sizeof(Char)) == 0);
#endif
#endif
-
- // Simplest case first: small strings are bitblitted
- if (!disableSSO && size <= maxSmallSize) {
- // Layout is: Char* data_, size_t size_, size_t capacity_
- static_assert(sizeof(*this) == sizeof(Char*) + 2 * sizeof(size_t),
- "fbstring has unexpected size");
- static_assert(sizeof(Char*) == sizeof(size_t),
- "fbstring size assumption violation");
- // sizeof(size_t) must be a power of 2
- static_assert((sizeof(size_t) & (sizeof(size_t) - 1)) == 0,
- "fbstring size assumption violation");
-
- // If data is aligned, use fast word-wise copying. Otherwise,
- // use conservative memcpy.
- // The word-wise path reads bytes which are outside the range of
- // the string, and makes ASan unhappy, so we disable it when
- // compiling with ASan.
-#ifndef FBSTRING_SANITIZE_ADDRESS
- if ((reinterpret_cast<size_t>(data) & (sizeof(size_t) - 1)) == 0) {
- const size_t byteSize = size * sizeof(Char);
- constexpr size_t wordWidth = sizeof(size_t);
- switch ((byteSize + wordWidth - 1) / wordWidth) { // Number of words.
- case 3:
- ml_.capacity_ = reinterpret_cast<const size_t*>(data)[2];
- case 2:
- ml_.size_ = reinterpret_cast<const size_t*>(data)[1];
- case 1:
- ml_.data_ = *reinterpret_cast<Char**>(const_cast<Char*>(data));
- case 0:
- break;
- }
- } else
-#endif
- {
- if (size != 0) {
- fbstring_detail::pod_copy(data, data + size, small_);
- }
- }
- setSmallSize(size);
- } else {
- if (size <= maxMediumSize) {
- // Medium strings are allocated normally. Don't forget to
- // allocate one extra Char for the terminating null.
- auto const allocSize = goodMallocSize((1 + size) * sizeof(Char));
- ml_.data_ = static_cast<Char*>(checkedMalloc(allocSize));
- fbstring_detail::pod_copy(data, data + size, ml_.data_);
- ml_.size_ = size;
- ml_.setCapacity(allocSize / sizeof(Char) - 1, Category::isMedium);
- } else {
- // Large strings are allocated differently
- size_t effectiveCapacity = size;
- auto const newRC = RefCounted::create(data, & effectiveCapacity);
- ml_.data_ = newRC->data_;
- ml_.size_ = size;
- ml_.setCapacity(effectiveCapacity, Category::isLarge);
- }
- ml_.data_[size] = '\0';
- }
}
~fbstring_core() noexcept {
return c_str();
}
- Char * mutable_data() {
- auto const c = category();
- if (c == Category::isSmall) {
+ Char* mutableData() {
+ switch (category()) {
+ case Category::isSmall:
return small_;
+ case Category::isMedium:
+ return ml_.data_;
+ case Category::isLarge:
+ return mutableDataLarge();
}
- assert(c == Category::isMedium || c == Category::isLarge);
- if (c == Category::isLarge && RefCounted::refs(ml_.data_) > 1) {
- // Ensure unique.
- size_t effectiveCapacity = ml_.capacity();
- auto const newRC = RefCounted::create(& effectiveCapacity);
- // If this fails, someone placed the wrong capacity in an
- // fbstring.
- assert(effectiveCapacity >= ml_.capacity());
- // Also copies terminator.
- fbstring_detail::pod_copy(ml_.data_, ml_.data_ + ml_.size_ + 1,
- newRC->data_);
- RefCounted::decrementRefs(ml_.data_);
- ml_.data_ = newRC->data_;
- }
- return ml_.data_;
+ fbstring_detail::assume_unreachable();
}
const Char * c_str() const {
void shrink(const size_t delta) {
if (category() == Category::isSmall) {
- // Check for underflow
- assert(delta <= smallSize());
- setSmallSize(smallSize() - delta);
+ shrinkSmall(delta);
} else if (category() == Category::isMedium ||
RefCounted::refs(ml_.data_) == 1) {
- // Medium strings and unique large strings need no special
- // handling.
- assert(ml_.size_ >= delta);
- ml_.size_ -= delta;
- ml_.data_[ml_.size_] = '\0';
+ shrinkMedium(delta);
} else {
- assert(ml_.size_ >= delta);
- // Shared large string, must make unique. This is because of the
- // durn terminator must be written, which may trample the shared
- // data.
- if (delta) {
- fbstring_core(ml_.data_, ml_.size_ - delta).swap(*this);
- }
- // No need to write the terminator.
+ shrinkLarge(delta);
}
}
void reserve(size_t minCapacity, bool disableSSO = FBSTRING_DISABLE_SSO) {
- if (category() == Category::isLarge) {
- // Ensure unique
- if (RefCounted::refs(ml_.data_) > 1) {
- // We must make it unique regardless; in-place reallocation is
- // useless if the string is shared. In order to not surprise
- // people, reserve the new block at current capacity or
- // more. That way, a string's capacity never shrinks after a
- // call to reserve.
- minCapacity = std::max(minCapacity, ml_.capacity());
- auto const newRC = RefCounted::create(& minCapacity);
- // Also copies terminator.
- fbstring_detail::pod_copy(ml_.data_, ml_.data_ + ml_.size_ + 1,
- newRC->data_);
- RefCounted::decrementRefs(ml_.data_);
- ml_.data_ = newRC->data_;
- ml_.setCapacity(minCapacity, Category::isLarge);
- // size remains unchanged
- } else {
- // String is not shared, so let's try to realloc (if needed)
- if (minCapacity > ml_.capacity()) {
- // Asking for more memory
- auto const newRC =
- RefCounted::reallocate(ml_.data_, ml_.size_,
- ml_.capacity(), minCapacity);
- ml_.data_ = newRC->data_;
- ml_.setCapacity(minCapacity, Category::isLarge);
- }
- assert(capacity() >= minCapacity);
- }
- } else if (category() == Category::isMedium) {
- // String is not shared
- if (minCapacity <= ml_.capacity()) {
- return; // nothing to do, there's enough room
- }
- if (minCapacity <= maxMediumSize) {
- // Keep the string at medium size. Don't forget to allocate
- // one extra Char for the terminating null.
- size_t capacityBytes = goodMallocSize((1 + minCapacity) * sizeof(Char));
- // Also copies terminator.
- ml_.data_ = static_cast<Char *>(
- smartRealloc(
- ml_.data_,
- (ml_.size_ + 1) * sizeof(Char),
- (ml_.capacity() + 1) * sizeof(Char),
- capacityBytes));
- ml_.setCapacity(capacityBytes / sizeof(Char) - 1, Category::isMedium);
- } else {
- // Conversion from medium to large string
- fbstring_core nascent;
- // Will recurse to another branch of this function
- nascent.reserve(minCapacity);
- nascent.ml_.size_ = ml_.size_;
- // Also copies terminator.
- fbstring_detail::pod_copy(ml_.data_, ml_.data_ + ml_.size_ + 1,
- nascent.ml_.data_);
- nascent.swap(*this);
- assert(capacity() >= minCapacity);
- }
- } else {
- assert(category() == Category::isSmall);
- if (!disableSSO && minCapacity <= maxSmallSize) {
- // small
- // Nothing to do, everything stays put
- } else if (minCapacity <= maxMediumSize) {
- // medium
- // Don't forget to allocate one extra Char for the terminating null
- auto const allocSizeBytes =
- goodMallocSize((1 + minCapacity) * sizeof(Char));
- auto const pData = static_cast<Char*>(checkedMalloc(allocSizeBytes));
- auto const size = smallSize();
- // Also copies terminator.
- fbstring_detail::pod_copy(small_, small_ + size + 1, pData);
- ml_.data_ = pData;
- ml_.size_ = size;
- ml_.setCapacity(allocSizeBytes / sizeof(Char) - 1, Category::isMedium);
- } else {
- // large
- auto const newRC = RefCounted::create(& minCapacity);
- auto const size = smallSize();
- // Also copies terminator.
- fbstring_detail::pod_copy(small_, small_ + size + 1, newRC->data_);
- ml_.data_ = newRC->data_;
- ml_.size_ = size;
- ml_.setCapacity(minCapacity, Category::isLarge);
- assert(capacity() >= minCapacity);
- }
+ switch (category()) {
+ case Category::isSmall:
+ reserveSmall(minCapacity, disableSSO);
+ break;
+ case Category::isMedium:
+ reserveMedium(minCapacity);
+ break;
+ case Category::isLarge:
+ reserveLarge(minCapacity);
+ break;
+ default:
+ fbstring_detail::assume_unreachable();
}
assert(capacity() >= minCapacity);
}
- Char * expand_noinit(const size_t delta,
- bool expGrowth = false,
- bool disableSSO = FBSTRING_DISABLE_SSO) {
- // Strategy is simple: make room, then change size
- assert(capacity() >= size());
- size_t sz, newSz;
- if (category() == Category::isSmall) {
- sz = smallSize();
- newSz = sz + delta;
- if (!disableSSO && FBSTRING_LIKELY(newSz <= maxSmallSize)) {
- setSmallSize(newSz);
- return small_ + sz;
- }
- reserve(expGrowth ? std::max(newSz, 2 * maxSmallSize) : newSz);
- } else {
- sz = ml_.size_;
- newSz = sz + delta;
- if (FBSTRING_UNLIKELY(newSz > capacity())) {
- // ensures not shared
- reserve(expGrowth ? std::max(newSz, 1 + capacity() * 3 / 2) : newSz);
- }
- }
- assert(capacity() >= newSz);
- // Category can't be small - we took care of that above
- assert(category() == Category::isMedium || category() == Category::isLarge);
- ml_.size_ = newSz;
- ml_.data_[newSz] = '\0';
- assert(size() == newSz);
- return ml_.data_ + sz;
- }
+ Char* expandNoinit(
+ const size_t delta,
+ bool expGrowth = false,
+ bool disableSSO = FBSTRING_DISABLE_SSO);
void push_back(Char c) {
- *expand_noinit(1, /* expGrowth = */ true) = c;
+ *expandNoinit(1, /* expGrowth = */ true) = c;
}
size_t size() const {
// For large-sized strings, a multi-referenced chunk has no
// available capacity. This is because any attempt to append
// data would trigger a new allocation.
- if (RefCounted::refs(ml_.data_) > 1) return ml_.size_;
+ if (RefCounted::refs(ml_.data_) > 1) {
+ return ml_.size_;
+ }
default: {}
}
return ml_.capacity();
static RefCounted * create(const Char * data, size_t * size) {
const size_t effectiveSize = *size;
auto result = create(size);
- fbstring_detail::pod_copy(data, data + effectiveSize, result->data_);
+ fbstring_detail::podCopy(data, data + effectiveSize, result->data_);
return result;
}
small_[s] = '\0';
assert(category() == Category::isSmall && size() == s);
}
+
+ void copySmall(const fbstring_core&);
+ void copyMedium(const fbstring_core&);
+ void copyLarge(const fbstring_core&);
+
+ void initSmall(const Char* data, size_t size);
+ void initMedium(const Char* data, size_t size);
+ void initLarge(const Char* data, size_t size);
+
+ void reserveSmall(size_t minCapacity, bool disableSSO);
+ void reserveMedium(size_t minCapacity);
+ void reserveLarge(size_t minCapacity);
+
+ void shrinkSmall(size_t delta);
+ void shrinkMedium(size_t delta);
+ void shrinkLarge(size_t delta);
+
+ Char* mutableDataLarge();
};
+template <class Char>
+inline void fbstring_core<Char>::copySmall(const fbstring_core& rhs) {
+ static_assert(offsetof(MediumLarge, data_) == 0, "fbstring layout failure");
+ static_assert(
+ offsetof(MediumLarge, size_) == sizeof(ml_.data_),
+ "fbstring layout failure");
+ static_assert(
+ offsetof(MediumLarge, capacity_) == 2 * sizeof(ml_.data_),
+ "fbstring layout failure");
+ // Just write the whole thing, don't look at details. In
+ // particular we need to copy capacity anyway because we want
+ // to set the size (don't forget that the last character,
+ // which stores a short string's length, is shared with the
+ // ml_.capacity field).
+ ml_ = rhs.ml_;
+ assert(category() == Category::isSmall && this->size() == rhs.size());
+}
+
+template <class Char>
+inline void fbstring_core<Char>::copyMedium(const fbstring_core& rhs) {
+ // Medium strings are copied eagerly. Don't forget to allocate
+ // one extra Char for the null terminator.
+ auto const allocSize = goodMallocSize((1 + rhs.ml_.size_) * sizeof(Char));
+ ml_.data_ = static_cast<Char*>(checkedMalloc(allocSize));
+ // Also copies terminator.
+ fbstring_detail::podCopy(
+ rhs.ml_.data_, rhs.ml_.data_ + rhs.ml_.size_ + 1, ml_.data_);
+ ml_.size_ = rhs.ml_.size_;
+ ml_.setCapacity(allocSize / sizeof(Char) - 1, Category::isMedium);
+ assert(category() == Category::isMedium);
+}
+
+template <class Char>
+inline void fbstring_core<Char>::copyLarge(const fbstring_core& rhs) {
+ // Large strings are just refcounted
+ ml_ = rhs.ml_;
+ RefCounted::incrementRefs(ml_.data_);
+ assert(category() == Category::isLarge && size() == rhs.size());
+}
+
+// Small strings are bitblitted
+template <class Char>
+inline void fbstring_core<Char>::initSmall(
+ const Char* const data, const size_t size) {
+ // Layout is: Char* data_, size_t size_, size_t capacity_
+ static_assert(
+ sizeof(*this) == sizeof(Char*) + 2 * sizeof(size_t),
+ "fbstring has unexpected size");
+ static_assert(
+ sizeof(Char*) == sizeof(size_t), "fbstring size assumption violation");
+ // sizeof(size_t) must be a power of 2
+ static_assert(
+ (sizeof(size_t) & (sizeof(size_t) - 1)) == 0,
+ "fbstring size assumption violation");
+
+// If data is aligned, use fast word-wise copying. Otherwise,
+// use conservative memcpy.
+// The word-wise path reads bytes which are outside the range of
+// the string, and makes ASan unhappy, so we disable it when
+// compiling with ASan.
+#ifndef FBSTRING_SANITIZE_ADDRESS
+ if ((reinterpret_cast<size_t>(data) & (sizeof(size_t) - 1)) == 0) {
+ const size_t byteSize = size * sizeof(Char);
+ constexpr size_t wordWidth = sizeof(size_t);
+ switch ((byteSize + wordWidth - 1) / wordWidth) { // Number of words.
+ case 3:
+ ml_.capacity_ = reinterpret_cast<const size_t*>(data)[2];
+ case 2:
+ ml_.size_ = reinterpret_cast<const size_t*>(data)[1];
+ case 1:
+ ml_.data_ = *reinterpret_cast<Char**>(const_cast<Char*>(data));
+ case 0:
+ break;
+ }
+ } else
+#endif
+ {
+ if (size != 0) {
+ fbstring_detail::podCopy(data, data + size, small_);
+ }
+ }
+ setSmallSize(size);
+}
+
+template <class Char>
+inline void fbstring_core<Char>::initMedium(
+ const Char* const data, const size_t size) {
+ // Medium strings are allocated normally. Don't forget to
+ // allocate one extra Char for the terminating null.
+ auto const allocSize = goodMallocSize((1 + size) * sizeof(Char));
+ ml_.data_ = static_cast<Char*>(checkedMalloc(allocSize));
+ fbstring_detail::podCopy(data, data + size, ml_.data_);
+ ml_.size_ = size;
+ ml_.setCapacity(allocSize / sizeof(Char) - 1, Category::isMedium);
+ ml_.data_[size] = '\0';
+}
+
+template <class Char>
+inline void fbstring_core<Char>::initLarge(
+ const Char* const data, const size_t size) {
+ // Large strings are allocated differently
+ size_t effectiveCapacity = size;
+ auto const newRC = RefCounted::create(data, &effectiveCapacity);
+ ml_.data_ = newRC->data_;
+ ml_.size_ = size;
+ ml_.setCapacity(effectiveCapacity, Category::isLarge);
+ ml_.data_[size] = '\0';
+}
+
+template <class Char>
+inline Char* fbstring_core<Char>::mutableDataLarge() {
+ assert(category() == Category::isLarge);
+ if (RefCounted::refs(ml_.data_) > 1) {
+ // Ensure unique.
+ size_t effectiveCapacity = ml_.capacity();
+ auto const newRC = RefCounted::create(&effectiveCapacity);
+ // If this fails, someone placed the wrong capacity in an
+ // fbstring.
+ assert(effectiveCapacity >= ml_.capacity());
+ // Also copies terminator.
+ fbstring_detail::podCopy(
+ ml_.data_, ml_.data_ + ml_.size_ + 1, newRC->data_);
+ RefCounted::decrementRefs(ml_.data_);
+ ml_.data_ = newRC->data_;
+ }
+ return ml_.data_;
+}
+
+template <class Char>
+inline void fbstring_core<Char>::reserveLarge(size_t minCapacity) {
+ assert(category() == Category::isLarge);
+ // Ensure unique
+ if (RefCounted::refs(ml_.data_) > 1) {
+ // We must make it unique regardless; in-place reallocation is
+ // useless if the string is shared. In order to not surprise
+ // people, reserve the new block at current capacity or
+ // more. That way, a string's capacity never shrinks after a
+ // call to reserve.
+ minCapacity = std::max(minCapacity, ml_.capacity());
+ auto const newRC = RefCounted::create(&minCapacity);
+ // Also copies terminator.
+ fbstring_detail::podCopy(
+ ml_.data_, ml_.data_ + ml_.size_ + 1, newRC->data_);
+ RefCounted::decrementRefs(ml_.data_);
+ ml_.data_ = newRC->data_;
+ ml_.setCapacity(minCapacity, Category::isLarge);
+ // size remains unchanged
+ } else {
+ // String is not shared, so let's try to realloc (if needed)
+ if (minCapacity > ml_.capacity()) {
+ // Asking for more memory
+ auto const newRC = RefCounted::reallocate(
+ ml_.data_, ml_.size_, ml_.capacity(), minCapacity);
+ ml_.data_ = newRC->data_;
+ ml_.setCapacity(minCapacity, Category::isLarge);
+ }
+ assert(capacity() >= minCapacity);
+ }
+}
+
+template <class Char>
+inline void fbstring_core<Char>::reserveMedium(const size_t minCapacity) {
+ assert(category() == Category::isMedium);
+ // String is not shared
+ if (minCapacity <= ml_.capacity()) {
+ return; // nothing to do, there's enough room
+ }
+ if (minCapacity <= maxMediumSize) {
+ // Keep the string at medium size. Don't forget to allocate
+ // one extra Char for the terminating null.
+ size_t capacityBytes = goodMallocSize((1 + minCapacity) * sizeof(Char));
+ // Also copies terminator.
+ ml_.data_ = static_cast<Char*>(smartRealloc(
+ ml_.data_,
+ (ml_.size_ + 1) * sizeof(Char),
+ (ml_.capacity() + 1) * sizeof(Char),
+ capacityBytes));
+ ml_.setCapacity(capacityBytes / sizeof(Char) - 1, Category::isMedium);
+ } else {
+ // Conversion from medium to large string
+ fbstring_core nascent;
+ // Will recurse to another branch of this function
+ nascent.reserve(minCapacity);
+ nascent.ml_.size_ = ml_.size_;
+ // Also copies terminator.
+ fbstring_detail::podCopy(
+ ml_.data_, ml_.data_ + ml_.size_ + 1, nascent.ml_.data_);
+ nascent.swap(*this);
+ assert(capacity() >= minCapacity);
+ }
+}
+
+template <class Char>
+inline void fbstring_core<Char>::reserveSmall(
+ size_t minCapacity, const bool disableSSO) {
+ assert(category() == Category::isSmall);
+ if (!disableSSO && minCapacity <= maxSmallSize) {
+ // small
+ // Nothing to do, everything stays put
+ } else if (minCapacity <= maxMediumSize) {
+ // medium
+ // Don't forget to allocate one extra Char for the terminating null
+ auto const allocSizeBytes =
+ goodMallocSize((1 + minCapacity) * sizeof(Char));
+ auto const pData = static_cast<Char*>(checkedMalloc(allocSizeBytes));
+ auto const size = smallSize();
+ // Also copies terminator.
+ fbstring_detail::podCopy(small_, small_ + size + 1, pData);
+ ml_.data_ = pData;
+ ml_.size_ = size;
+ ml_.setCapacity(allocSizeBytes / sizeof(Char) - 1, Category::isMedium);
+ } else {
+ // large
+ auto const newRC = RefCounted::create(&minCapacity);
+ auto const size = smallSize();
+ // Also copies terminator.
+ fbstring_detail::podCopy(small_, small_ + size + 1, newRC->data_);
+ ml_.data_ = newRC->data_;
+ ml_.size_ = size;
+ ml_.setCapacity(minCapacity, Category::isLarge);
+ assert(capacity() >= minCapacity);
+ }
+}
+
+template <class Char>
+inline Char* fbstring_core<Char>::expandNoinit(
+ const size_t delta,
+ bool expGrowth, /* = false */
+ bool disableSSO /* = FBSTRING_DISABLE_SSO */) {
+ // Strategy is simple: make room, then change size
+ assert(capacity() >= size());
+ size_t sz, newSz;
+ if (category() == Category::isSmall) {
+ sz = smallSize();
+ newSz = sz + delta;
+ if (!disableSSO && FBSTRING_LIKELY(newSz <= maxSmallSize)) {
+ setSmallSize(newSz);
+ return small_ + sz;
+ }
+ reserveSmall(
+ expGrowth ? std::max(newSz, 2 * maxSmallSize) : newSz, disableSSO);
+ } else {
+ sz = ml_.size_;
+ newSz = sz + delta;
+ if (FBSTRING_UNLIKELY(newSz > capacity())) {
+ // ensures not shared
+ reserve(expGrowth ? std::max(newSz, 1 + capacity() * 3 / 2) : newSz);
+ }
+ }
+ assert(capacity() >= newSz);
+ // Category can't be small - we took care of that above
+ assert(category() == Category::isMedium || category() == Category::isLarge);
+ ml_.size_ = newSz;
+ ml_.data_[newSz] = '\0';
+ assert(size() == newSz);
+ return ml_.data_ + sz;
+}
+
+template <class Char>
+inline void fbstring_core<Char>::shrinkSmall(const size_t delta) {
+ // Check for underflow
+ assert(delta <= smallSize());
+ setSmallSize(smallSize() - delta);
+}
+
+template <class Char>
+inline void fbstring_core<Char>::shrinkMedium(const size_t delta) {
+ // Medium strings and unique large strings need no special
+ // handling.
+ assert(ml_.size_ >= delta);
+ ml_.size_ -= delta;
+ ml_.data_[ml_.size_] = '\0';
+}
+
+template <class Char>
+inline void fbstring_core<Char>::shrinkLarge(const size_t delta) {
+ assert(ml_.size_ >= delta);
+ // Shared large string, must make unique. This is because of the
+ // durn terminator must be written, which may trample the shared
+ // data.
+ if (delta) {
+ fbstring_core(ml_.data_, ml_.size_ - delta).swap(*this);
+ }
+ // No need to write the terminator.
+}
+
#ifndef _LIBSTDCXX_FBSTRING
/**
* Dummy fbstring core that uses an actual std::string. This doesn't
const Char * data() const {
return backend_.data();
}
- Char * mutable_data() {
- //assert(!backend_.empty());
- return &*backend_.begin();
+ Char* mutableData() {
+ return const_cast<Char*>(backend_.data());
}
void shrink(size_t delta) {
assert(delta <= size());
backend_.resize(size() - delta);
}
- Char * expand_noinit(size_t delta) {
+ Char* expandNoinit(size_t delta) {
auto const sz = size();
backend_.resize(size() + delta);
return backend_.data() + sz;
bool condition,
void (*throw_exc)(const char*),
const char* msg) {
- if (!condition) throw_exc(msg);
+ if (!condition) {
+ throw_exc(msg);
+ }
}
bool isSane() const {
struct Invariant;
friend struct Invariant;
struct Invariant {
+ Invariant& operator=(const Invariant&) = delete;
#ifndef NDEBUG
explicit Invariant(const basic_fbstring& s) : s_(s) {
assert(s_.isSane());
#else
explicit Invariant(const basic_fbstring&) {}
#endif
- Invariant& operator=(const Invariant&);
};
public:
#endif
> const_reverse_iterator;
- static const size_type npos; // = size_type(-1)
+ static constexpr size_type npos = size_type(-1);
typedef std::true_type IsRelocatable;
private:
static void procrustes(size_type& n, size_type nmax) {
- if (n > nmax) n = nmax;
+ if (n > nmax) {
+ n = nmax;
+ }
}
+ static size_type traitsLength(const value_type* s);
+
public:
// C++11 21.4.2 construct/copy/destroy
}
/* implicit */ basic_fbstring(const value_type* s, const A& /*a*/ = A())
- : store_(s, s
- ? traits_type::length(s)
- : (std::__throw_logic_error(
- "basic_fbstring: null pointer initializer not valid"),
- 0)) {
+ : store_(s, basic_fbstring::traitsLength(s)) {
}
basic_fbstring(const value_type* s, size_type n, const A& /*a*/ = A())
}
basic_fbstring(size_type n, value_type c, const A& /*a*/ = A()) {
- auto const pData = store_.expand_noinit(n);
- fbstring_detail::pod_fill(pData, pData + n, c);
+ auto const pData = store_.expandNoinit(n);
+ fbstring_detail::podFill(pData, pData + n, c);
}
template <class InIt>
- basic_fbstring(InIt begin, InIt end,
- typename std::enable_if<
- !std::is_same<typename std::remove_const<InIt>::type,
- value_type*>::value, const A>::type & /*a*/ = A()) {
+ basic_fbstring(
+ InIt begin,
+ InIt end,
+ typename std::enable_if<
+ !std::is_same<InIt, value_type*>::value,
+ const A>::type& /*a*/ = A()) {
assign(begin, end);
}
// Specialization for const char*, const char*
- basic_fbstring(const value_type* b, const value_type* e)
+ basic_fbstring(const value_type* b, const value_type* e, const A& /*a*/ = A())
: store_(b, e - b) {
}
~basic_fbstring() noexcept {
}
- basic_fbstring& operator=(const basic_fbstring& lhs) {
- Invariant checker(*this);
-
- if (FBSTRING_UNLIKELY(&lhs == this)) {
- return *this;
- }
-
- return assign(lhs.data(), lhs.size());
- }
+ basic_fbstring& operator=(const basic_fbstring& lhs);
// Move assignment
- basic_fbstring& operator=(basic_fbstring&& goner) noexcept {
- if (FBSTRING_UNLIKELY(&goner == this)) {
- // Compatibility with std::basic_string<>,
- // C++11 21.4.2 [string.cons] / 23 requires self-move-assignment support.
- return *this;
- }
- // No need of this anymore
- this->~basic_fbstring();
- // Move the goner into this
- new (&store_) Storage(std::move(goner.store_));
- return *this;
- }
+ basic_fbstring& operator=(basic_fbstring&& goner) noexcept;
#ifndef _LIBSTDCXX_FBSTRING
// Compatibility with std::string
return assign(s);
}
- basic_fbstring& operator=(value_type c) {
- Invariant checker(*this);
-
- if (empty()) {
- store_.expand_noinit(1);
- } else if (store_.isShared()) {
- basic_fbstring(1, c).swap(*this);
- return *this;
- } else {
- store_.shrink(size() - 1);
- }
- front() = c;
- return *this;
- }
+ basic_fbstring& operator=(value_type c);
basic_fbstring& operator=(std::initializer_list<value_type> il) {
return assign(il.begin(), il.end());
}
// C++11 21.4.3 iterators:
- iterator begin() { return store_.mutable_data(); }
+ iterator begin() {
+ return store_.mutableData();
+ }
- const_iterator begin() const { return store_.data(); }
+ const_iterator begin() const {
+ return store_.data();
+ }
- const_iterator cbegin() const { return begin(); }
+ const_iterator cbegin() const {
+ return begin();
+ }
iterator end() {
- return store_.mutable_data() + store_.size();
+ return store_.mutableData() + store_.size();
}
const_iterator end() const {
return std::numeric_limits<size_type>::max();
}
- void resize(const size_type n, const value_type c = value_type()) {
- Invariant checker(*this);
-
- auto size = this->size();
- if (n <= size) {
- store_.shrink(size - n);
- } else {
- auto const delta = n - size;
- auto pData = store_.expand_noinit(delta);
- fbstring_detail::pod_fill(pData, pData + delta, c);
- }
- assert(this->size() == n);
- }
+ void resize(size_type n, value_type c = value_type());
size_type capacity() const { return store_.capacity(); }
return *this;
}
- basic_fbstring& append(const basic_fbstring& str) {
-#ifndef NDEBUG
- auto desiredSize = size() + str.size();
-#endif
- append(str.data(), str.size());
- assert(size() == desiredSize);
- return *this;
- }
+ basic_fbstring& append(const basic_fbstring& str);
- basic_fbstring& append(const basic_fbstring& str, const size_type pos,
- size_type n) {
- const size_type sz = str.size();
- enforce(pos <= sz, std::__throw_out_of_range, "");
- procrustes(n, sz - pos);
- return append(str.data() + pos, n);
- }
+ basic_fbstring&
+ append(const basic_fbstring& str, const size_type pos, size_type n);
- basic_fbstring& append(const value_type* s, size_type n) {
- Invariant checker(*this);
-
- if (FBSTRING_UNLIKELY(!n)) {
- // Unlikely but must be done
- return *this;
- }
- auto const oldSize = size();
- auto const oldData = data();
- auto pData = store_.expand_noinit(n, /* expGrowth = */ true);
-
- // Check for aliasing (rare). We could use "<=" here but in theory
- // those do not work for pointers unless the pointers point to
- // elements in the same array. For that reason we use
- // std::less_equal, which is guaranteed to offer a total order
- // over pointers. See discussion at http://goo.gl/Cy2ya for more
- // info.
- std::less_equal<const value_type*> le;
- if (FBSTRING_UNLIKELY(le(oldData, s) && !le(oldData + oldSize, s))) {
- assert(le(s + n, oldData + oldSize));
- // expand_noinit() could have moved the storage, restore the source.
- s = data() + (s - oldData);
- fbstring_detail::pod_move(s, s + n, pData);
- } else {
- fbstring_detail::pod_copy(s, s + n, pData);
- }
-
- assert(size() == oldSize + n);
- return *this;
- }
+ basic_fbstring& append(const value_type* s, size_type n);
basic_fbstring& append(const value_type* s) {
return append(s, traits_type::length(s));
}
- basic_fbstring& append(size_type n, value_type c) {
- Invariant checker(*this);
- auto pData = store_.expand_noinit(n, /* expGrowth = */ true);
- fbstring_detail::pod_fill(pData, pData + n, c);
- return *this;
- }
+ basic_fbstring& append(size_type n, value_type c);
template<class InputIterator>
basic_fbstring& append(InputIterator first, InputIterator last) {
return *this = std::move(str);
}
- basic_fbstring& assign(const basic_fbstring& str, const size_type pos,
- size_type n) {
- const size_type sz = str.size();
- enforce(pos <= sz, std::__throw_out_of_range, "");
- procrustes(n, sz - pos);
- return assign(str.data() + pos, n);
- }
-
- basic_fbstring& assign(const value_type* s, const size_type n) {
- Invariant checker(*this);
-
- if (n == 0) {
- resize(0);
- } else if (size() >= n) {
- // s can alias this, we need to use pod_move.
- fbstring_detail::pod_move(s, s + n, store_.mutable_data());
- store_.shrink(size() - n);
- assert(size() == n);
- } else {
- // If n is larger than size(), s cannot alias this string's
- // storage.
- resize(0);
- // Do not use exponential growth here: assign() should be tight,
- // to mirror the behavior of the equivalent constructor.
- fbstring_detail::pod_copy(s, s + n, store_.expand_noinit(n));
- }
+ basic_fbstring&
+ assign(const basic_fbstring& str, const size_type pos, size_type n);
- assert(size() == n);
- return *this;
- }
+ basic_fbstring& assign(const value_type* s, const size_type n);
basic_fbstring& assign(const value_type* s) {
return assign(s, traits_type::length(s));
#ifndef _LIBSTDCXX_FBSTRING
private:
typedef std::basic_istream<value_type, traits_type> istream_type;
+ istream_type& getlineImpl(istream_type& is, value_type delim);
public:
friend inline istream_type& getline(istream_type& is,
basic_fbstring& str,
value_type delim) {
- Invariant checker(str);
-
- str.clear();
- size_t size = 0;
- while (true) {
- size_t avail = str.capacity() - size;
- // fbstring has 1 byte extra capacity for the null terminator,
- // and getline null-terminates the read string.
- is.getline(str.store_.expand_noinit(avail), avail + 1, delim);
- size += is.gcount();
-
- if (is.bad() || is.eof() || !is.fail()) {
- // Done by either failure, end of file, or normal read.
- if (!is.bad() && !is.eof()) {
- --size; // gcount() also accounts for the delimiter.
- }
- str.resize(size);
- break;
- }
-
- assert(size == str.size());
- assert(size == str.capacity());
- // Start at minimum allocation 63 + terminator = 64.
- str.reserve(std::max<size_t>(63, 3 * size / 2));
- // Clear the error so we can continue reading.
- is.clear();
- }
- return is;
+ return str.getlineImpl(is, delim);
}
friend inline istream_type& getline(istream_type& is, basic_fbstring& str) {
#endif
private:
- template <int i> class Selector {};
+ iterator
+ insertImplDiscr(const_iterator i, size_type n, value_type c, std::true_type);
- iterator insertImplDiscr(const_iterator i,
- size_type n, value_type c, Selector<1>) {
- Invariant checker(*this);
+ template <class InputIter>
+ iterator
+ insertImplDiscr(const_iterator i, InputIter b, InputIter e, std::false_type);
- assert(i >= cbegin() && i <= cend());
- const size_type pos = i - cbegin();
-
- auto oldSize = size();
- store_.expand_noinit(n, /* expGrowth = */ true);
- auto b = begin();
- fbstring_detail::pod_move(b + pos, b + oldSize, b + pos + n);
- fbstring_detail::pod_fill(b + pos, b + pos + n, c);
-
- return b + pos;
- }
-
- template<class InputIter>
- iterator insertImplDiscr(const_iterator i,
- InputIter b, InputIter e, Selector<0>) {
- return insertImpl(i, b, e,
- typename std::iterator_traits<InputIter>::iterator_category());
- }
-
- template <class FwdIterator>
- iterator insertImpl(const_iterator i,
- FwdIterator s1,
- FwdIterator s2,
- std::forward_iterator_tag) {
- Invariant checker(*this);
-
- assert(i >= cbegin() && i <= cend());
- const size_type pos = i - cbegin();
- auto n = std::distance(s1, s2);
- assert(n >= 0);
-
- auto oldSize = size();
- store_.expand_noinit(n, /* expGrowth = */ true);
- auto b = begin();
- fbstring_detail::pod_move(b + pos, b + oldSize, b + pos + n);
- std::copy(s1, s2, b + pos);
-
- return b + pos;
- }
-
- template <class InputIterator>
- iterator insertImpl(const_iterator i,
- InputIterator b, InputIterator e,
- std::input_iterator_tag) {
- const auto pos = i - cbegin();
- basic_fbstring temp(cbegin(), i);
- for (; b != e; ++b) {
- temp.push_back(*b);
- }
- temp.append(i, cend());
- swap(temp);
- return begin() + pos;
- }
+ template <class FwdIterator>
+ iterator insertImpl(
+ const_iterator i,
+ FwdIterator s1,
+ FwdIterator s2,
+ std::forward_iterator_tag);
+
+ template <class InputIterator>
+ iterator insertImpl(
+ const_iterator i,
+ InputIterator b,
+ InputIterator e,
+ std::input_iterator_tag);
public:
template <class ItOrLength, class ItOrChar>
iterator insert(const_iterator p, ItOrLength first_or_n, ItOrChar last_or_c) {
- Selector<std::numeric_limits<ItOrLength>::is_specialized> sel;
- return insertImplDiscr(p, first_or_n, last_or_c, sel);
+ using Sel = std::integral_constant<
+ bool,
+ std::numeric_limits<ItOrLength>::is_specialized>;
+ return insertImplDiscr(p, first_or_n, last_or_c, Sel());
}
iterator insert(const_iterator p, std::initializer_list<value_type> il) {
}
private:
- basic_fbstring& replaceImplDiscr(iterator i1, iterator i2,
- const value_type* s, size_type n,
- Selector<2>) {
- assert(i1 <= i2);
- assert(begin() <= i1 && i1 <= end());
- assert(begin() <= i2 && i2 <= end());
- return replace(i1, i2, s, s + n);
- }
-
- basic_fbstring& replaceImplDiscr(iterator i1, iterator i2,
- size_type n2, value_type c, Selector<1>) {
- const size_type n1 = i2 - i1;
- if (n1 > n2) {
- std::fill(i1, i1 + n2, c);
- erase(i1 + n2, i2);
- } else {
- std::fill(i1, i2, c);
- insert(i2, n2 - n1, c);
- }
- assert(isSane());
- return *this;
- }
-
- template <class InputIter>
- basic_fbstring& replaceImplDiscr(iterator i1, iterator i2,
- InputIter b, InputIter e,
- Selector<0>) {
- replaceImpl(i1, i2, b, e,
- typename std::iterator_traits<InputIter>::iterator_category());
- return *this;
- }
+ basic_fbstring& replaceImplDiscr(
+ iterator i1,
+ iterator i2,
+ const value_type* s,
+ size_type n,
+ std::integral_constant<int, 2>);
+
+ basic_fbstring& replaceImplDiscr(
+ iterator i1,
+ iterator i2,
+ size_type n2,
+ value_type c,
+ std::integral_constant<int, 1>);
+
+ template <class InputIter>
+ basic_fbstring& replaceImplDiscr(
+ iterator i1,
+ iterator i2,
+ InputIter b,
+ InputIter e,
+ std::integral_constant<int, 0>);
private:
template <class FwdIterator>
}
template <class FwdIterator>
- bool replaceAliased(iterator i1, iterator i2,
- FwdIterator s1, FwdIterator s2, std::true_type) {
- static const std::less_equal<const value_type*> le =
- std::less_equal<const value_type*>();
- const bool aliased = le(&*begin(), &*s1) && le(&*s1, &*end());
- if (!aliased) {
- return false;
- }
- // Aliased replace, copy to new string
- basic_fbstring temp;
- temp.reserve(size() - (i2 - i1) + std::distance(s1, s2));
- temp.append(begin(), i1).append(s1, s2).append(i2, end());
- swap(temp);
- return true;
- }
+ bool replaceAliased(
+ iterator i1,
+ iterator i2,
+ FwdIterator s1,
+ FwdIterator s2,
+ std::true_type);
template <class FwdIterator>
- void replaceImpl(iterator i1, iterator i2,
- FwdIterator s1, FwdIterator s2, std::forward_iterator_tag) {
- Invariant checker(*this);
-
- // Handle aliased replace
- if (replaceAliased(i1, i2, s1, s2,
- std::integral_constant<bool,
- std::is_same<FwdIterator, iterator>::value ||
- std::is_same<FwdIterator, const_iterator>::value>())) {
- return;
- }
-
- auto const n1 = i2 - i1;
- assert(n1 >= 0);
- auto const n2 = std::distance(s1, s2);
- assert(n2 >= 0);
-
- if (n1 > n2) {
- // shrinks
- std::copy(s1, s2, i1);
- erase(i1 + n2, i2);
- } else {
- // grows
- fbstring_detail::copy_n(s1, n1, i1);
- std::advance(s1, n1);
- insert(i2, s1, s2);
- }
- assert(isSane());
- }
+ void replaceImpl(
+ iterator i1,
+ iterator i2,
+ FwdIterator s1,
+ FwdIterator s2,
+ std::forward_iterator_tag);
template <class InputIterator>
- void replaceImpl(iterator i1, iterator i2,
- InputIterator b, InputIterator e, std::input_iterator_tag) {
- basic_fbstring temp(begin(), i1);
- temp.append(b, e).append(i2, end());
- swap(temp);
- }
+ void replaceImpl(
+ iterator i1,
+ iterator i2,
+ InputIterator b,
+ InputIterator e,
+ std::input_iterator_tag);
-public:
+ public:
template <class T1, class T2>
basic_fbstring& replace(iterator i1, iterator i2,
T1 first_or_n_or_s, T2 last_or_c_or_n) {
- const bool
- num1 = std::numeric_limits<T1>::is_specialized,
- num2 = std::numeric_limits<T2>::is_specialized;
- return replaceImplDiscr(
- i1, i2, first_or_n_or_s, last_or_c_or_n,
- Selector<num1 ? (num2 ? 1 : -1) : (num2 ? 2 : 0)>());
+ constexpr bool num1 = std::numeric_limits<T1>::is_specialized,
+ num2 = std::numeric_limits<T2>::is_specialized;
+ using Sel =
+ std::integral_constant<int, num1 ? (num2 ? 1 : -1) : (num2 ? 2 : 0)>;
+ return replaceImplDiscr(i1, i2, first_or_n_or_s, last_or_c_or_n, Sel());
}
size_type copy(value_type* s, size_type n, size_type pos = 0) const {
procrustes(n, size() - pos);
if (n != 0) {
- fbstring_detail::pod_copy(data() + pos, data() + pos + n, s);
+ fbstring_detail::podCopy(data() + pos, data() + pos + n, s);
}
return n;
}
return find(str.data(), pos, str.length());
}
- size_type find(const value_type* needle, const size_type pos,
- const size_type nsize) const {
- auto const size = this->size();
- // nsize + pos can overflow (eg pos == npos), guard against that by checking
- // that nsize + pos does not wrap around.
- if (nsize + pos > size || nsize + pos < pos) return npos;
-
- if (nsize == 0) return pos;
- // Don't use std::search, use a Boyer-Moore-like trick by comparing
- // the last characters first
- auto const haystack = data();
- auto const nsize_1 = nsize - 1;
- auto const lastNeedle = needle[nsize_1];
-
- // Boyer-Moore skip value for the last char in the needle. Zero is
- // not a valid value; skip will be computed the first time it's
- // needed.
- size_type skip = 0;
-
- const E * i = haystack + pos;
- auto iEnd = haystack + size - nsize_1;
-
- while (i < iEnd) {
- // Boyer-Moore: match the last element in the needle
- while (i[nsize_1] != lastNeedle) {
- if (++i == iEnd) {
- // not found
- return npos;
- }
- }
- // Here we know that the last char matches
- // Continue in pedestrian mode
- for (size_t j = 0; ; ) {
- assert(j < nsize);
- if (i[j] != needle[j]) {
- // Not found, we can skip
- // Compute the skip value lazily
- if (skip == 0) {
- skip = 1;
- while (skip <= nsize_1 && needle[nsize_1 - skip] != lastNeedle) {
- ++skip;
- }
- }
- i += skip;
- break;
- }
- // Check if done searching
- if (++j == nsize) {
- // Yay
- return i - haystack;
- }
- }
- }
- return npos;
- }
+ size_type find(const value_type* needle, size_type pos, size_type nsize)
+ const;
size_type find(const value_type* s, size_type pos = 0) const {
return find(s, pos, traits_type::length(s));
return rfind(str.data(), pos, str.length());
}
- size_type rfind(const value_type* s, size_type pos, size_type n) const {
- if (n > length()) return npos;
- pos = std::min(pos, length() - n);
- if (n == 0) return pos;
-
- const_iterator i(begin() + pos);
- for (; ; --i) {
- if (traits_type::eq(*i, *s)
- && traits_type::compare(&*i, s, n) == 0) {
- return i - begin();
- }
- if (i == begin()) break;
- }
- return npos;
- }
+ size_type rfind(const value_type* s, size_type pos, size_type n) const;
size_type rfind(const value_type* s, size_type pos = npos) const {
return rfind(s, pos, traits_type::length(s));
return find_first_of(str.data(), pos, str.length());
}
- size_type find_first_of(const value_type* s,
- size_type pos, size_type n) const {
- if (pos > length() || n == 0) return npos;
- const_iterator i(begin() + pos),
- finish(end());
- for (; i != finish; ++i) {
- if (traits_type::find(s, n, *i) != 0) {
- return i - begin();
- }
- }
- return npos;
- }
+ size_type find_first_of(const value_type* s, size_type pos, size_type n)
+ const;
size_type find_first_of(const value_type* s, size_type pos = 0) const {
return find_first_of(s, pos, traits_type::length(s));
return find_first_of(&c, pos, 1);
}
- size_type find_last_of (const basic_fbstring& str,
- size_type pos = npos) const {
+ size_type find_last_of(const basic_fbstring& str, size_type pos = npos)
+ const {
return find_last_of(str.data(), pos, str.length());
}
- size_type find_last_of (const value_type* s, size_type pos,
- size_type n) const {
- if (!empty() && n > 0) {
- pos = std::min(pos, length() - 1);
- const_iterator i(begin() + pos);
- for (;; --i) {
- if (traits_type::find(s, n, *i) != 0) {
- return i - begin();
- }
- if (i == begin()) break;
- }
- }
- return npos;
- }
+ size_type find_last_of(const value_type* s, size_type pos, size_type n) const;
size_type find_last_of (const value_type* s,
size_type pos = npos) const {
return find_first_not_of(str.data(), pos, str.size());
}
- size_type find_first_not_of(const value_type* s, size_type pos,
- size_type n) const {
- if (pos < length()) {
- const_iterator
- i(begin() + pos),
- finish(end());
- for (; i != finish; ++i) {
- if (traits_type::find(s, n, *i) == 0) {
- return i - begin();
- }
- }
- }
- return npos;
- }
+ size_type find_first_not_of(const value_type* s, size_type pos, size_type n)
+ const;
size_type find_first_not_of(const value_type* s,
size_type pos = 0) const {
return find_last_not_of(str.data(), pos, str.length());
}
- size_type find_last_not_of(const value_type* s, size_type pos,
- size_type n) const {
- if (!this->empty()) {
- pos = std::min(pos, size() - 1);
- const_iterator i(begin() + pos);
- for (;; --i) {
- if (traits_type::find(s, n, *i) == 0) {
- return i - begin();
- }
- if (i == begin()) break;
- }
- }
- return npos;
- }
+ size_type find_last_not_of(const value_type* s, size_type pos, size_type n)
+ const;
size_type find_last_not_of(const value_type* s,
size_type pos = npos) const {
basic_fbstring substr(size_type pos = 0, size_type n = npos) && {
enforce(pos <= size(), std::__throw_out_of_range, "");
erase(0, pos);
- if (n < size()) resize(n);
+ if (n < size()) {
+ resize(n);
+ }
return std::move(*this);
}
Storage store_;
};
+template <typename E, class T, class A, class S>
+inline typename basic_fbstring<E, T, A, S>::size_type
+basic_fbstring<E, T, A, S>::traitsLength(const value_type* s) {
+ return s ? traits_type::length(s)
+ : (std::__throw_logic_error(
+ "basic_fbstring: null pointer initializer not valid"),
+ 0);
+}
+
+template <typename E, class T, class A, class S>
+inline basic_fbstring<E, T, A, S>& basic_fbstring<E, T, A, S>::operator=(
+ const basic_fbstring& lhs) {
+ Invariant checker(*this);
+
+ if (FBSTRING_UNLIKELY(&lhs == this)) {
+ return *this;
+ }
+
+ return assign(lhs.data(), lhs.size());
+}
+
+// Move assignment
+template <typename E, class T, class A, class S>
+inline basic_fbstring<E, T, A, S>& basic_fbstring<E, T, A, S>::operator=(
+ basic_fbstring&& goner) noexcept {
+ if (FBSTRING_UNLIKELY(&goner == this)) {
+ // Compatibility with std::basic_string<>,
+ // C++11 21.4.2 [string.cons] / 23 requires self-move-assignment support.
+ return *this;
+ }
+ // No need of this anymore
+ this->~basic_fbstring();
+ // Move the goner into this
+ new (&store_) S(std::move(goner.store_));
+ return *this;
+}
+
+template <typename E, class T, class A, class S>
+inline basic_fbstring<E, T, A, S>& basic_fbstring<E, T, A, S>::operator=(
+ const value_type c) {
+ Invariant checker(*this);
+
+ if (empty()) {
+ store_.expandNoinit(1);
+ } else if (store_.isShared()) {
+ basic_fbstring(1, c).swap(*this);
+ return *this;
+ } else {
+ store_.shrink(size() - 1);
+ }
+ front() = c;
+ return *this;
+}
+
+template <typename E, class T, class A, class S>
+inline void basic_fbstring<E, T, A, S>::resize(
+ const size_type n, const value_type c /*= value_type()*/) {
+ Invariant checker(*this);
+
+ auto size = this->size();
+ if (n <= size) {
+ store_.shrink(size - n);
+ } else {
+ auto const delta = n - size;
+ auto pData = store_.expandNoinit(delta);
+ fbstring_detail::podFill(pData, pData + delta, c);
+ }
+ assert(this->size() == n);
+}
+
+template <typename E, class T, class A, class S>
+inline basic_fbstring<E, T, A, S>& basic_fbstring<E, T, A, S>::append(
+ const basic_fbstring& str) {
+#ifndef NDEBUG
+ auto desiredSize = size() + str.size();
+#endif
+ append(str.data(), str.size());
+ assert(size() == desiredSize);
+ return *this;
+}
+
+template <typename E, class T, class A, class S>
+inline basic_fbstring<E, T, A, S>& basic_fbstring<E, T, A, S>::append(
+ const basic_fbstring& str, const size_type pos, size_type n) {
+ const size_type sz = str.size();
+ enforce(pos <= sz, std::__throw_out_of_range, "");
+ procrustes(n, sz - pos);
+ return append(str.data() + pos, n);
+}
+
+template <typename E, class T, class A, class S>
+inline basic_fbstring<E, T, A, S>& basic_fbstring<E, T, A, S>::append(
+ const value_type* s, size_type n) {
+ Invariant checker(*this);
+
+ if (FBSTRING_UNLIKELY(!n)) {
+ // Unlikely but must be done
+ return *this;
+ }
+ auto const oldSize = size();
+ auto const oldData = data();
+ auto pData = store_.expandNoinit(n, /* expGrowth = */ true);
+
+ // Check for aliasing (rare). We could use "<=" here but in theory
+ // those do not work for pointers unless the pointers point to
+ // elements in the same array. For that reason we use
+ // std::less_equal, which is guaranteed to offer a total order
+ // over pointers. See discussion at http://goo.gl/Cy2ya for more
+ // info.
+ std::less_equal<const value_type*> le;
+ if (FBSTRING_UNLIKELY(le(oldData, s) && !le(oldData + oldSize, s))) {
+ assert(le(s + n, oldData + oldSize));
+ // expandNoinit() could have moved the storage, restore the source.
+ s = data() + (s - oldData);
+ fbstring_detail::podMove(s, s + n, pData);
+ } else {
+ fbstring_detail::podCopy(s, s + n, pData);
+ }
+
+ assert(size() == oldSize + n);
+ return *this;
+}
+
+template <typename E, class T, class A, class S>
+inline basic_fbstring<E, T, A, S>& basic_fbstring<E, T, A, S>::append(
+ size_type n, value_type c) {
+ Invariant checker(*this);
+ auto pData = store_.expandNoinit(n, /* expGrowth = */ true);
+ fbstring_detail::podFill(pData, pData + n, c);
+ return *this;
+}
+
+template <typename E, class T, class A, class S>
+inline basic_fbstring<E, T, A, S>& basic_fbstring<E, T, A, S>::assign(
+ const basic_fbstring& str, const size_type pos, size_type n) {
+ const size_type sz = str.size();
+ enforce(pos <= sz, std::__throw_out_of_range, "");
+ procrustes(n, sz - pos);
+ return assign(str.data() + pos, n);
+}
+
+template <typename E, class T, class A, class S>
+inline basic_fbstring<E, T, A, S>& basic_fbstring<E, T, A, S>::assign(
+ const value_type* s, const size_type n) {
+ Invariant checker(*this);
+
+ // s can alias this, we need to use podMove.
+ if (n == 0) {
+ resize(0);
+ } else if (size() >= n) {
+ // s can alias this, we need to use podMove.
+ fbstring_detail::podMove(s, s + n, store_.mutableData());
+ store_.shrink(size() - n);
+ assert(size() == n);
+ } else {
+ // If n is larger than size(), s cannot alias this string's
+ // storage.
+ resize(0);
+ // Do not use exponential growth here: assign() should be tight,
+ // to mirror the behavior of the equivalent constructor.
+ fbstring_detail::podCopy(s, s + n, store_.expandNoinit(n));
+ }
+
+ assert(size() == n);
+ return *this;
+}
+
+#ifndef _LIBSTDCXX_FBSTRING
+template <typename E, class T, class A, class S>
+inline typename basic_fbstring<E, T, A, S>::istream_type&
+basic_fbstring<E, T, A, S>::getlineImpl(istream_type & is, value_type delim) {
+ Invariant checker(*this);
+
+ clear();
+ size_t size = 0;
+ while (true) {
+ size_t avail = capacity() - size;
+ // fbstring has 1 byte extra capacity for the null terminator,
+ // and getline null-terminates the read string.
+ is.getline(store_.expandNoinit(avail), avail + 1, delim);
+ size += is.gcount();
+
+ if (is.bad() || is.eof() || !is.fail()) {
+ // Done by either failure, end of file, or normal read.
+ if (!is.bad() && !is.eof()) {
+ --size; // gcount() also accounts for the delimiter.
+ }
+ resize(size);
+ break;
+ }
+
+ assert(size == this->size());
+ assert(size == capacity());
+ // Start at minimum allocation 63 + terminator = 64.
+ reserve(std::max<size_t>(63, 3 * size / 2));
+ // Clear the error so we can continue reading.
+ is.clear();
+ }
+ return is;
+}
+#endif
+
+template <typename E, class T, class A, class S>
+inline typename basic_fbstring<E, T, A, S>::size_type
+basic_fbstring<E, T, A, S>::find(
+ const value_type* needle, const size_type pos, const size_type nsize)
+ const {
+ auto const size = this->size();
+ // nsize + pos can overflow (eg pos == npos), guard against that by checking
+ // that nsize + pos does not wrap around.
+ if (nsize + pos > size || nsize + pos < pos) {
+ return npos;
+ }
+
+ if (nsize == 0) {
+ return pos;
+ }
+ // Don't use std::search, use a Boyer-Moore-like trick by comparing
+ // the last characters first
+ auto const haystack = data();
+ auto const nsize_1 = nsize - 1;
+ auto const lastNeedle = needle[nsize_1];
+
+ // Boyer-Moore skip value for the last char in the needle. Zero is
+ // not a valid value; skip will be computed the first time it's
+ // needed.
+ size_type skip = 0;
+
+ const E* i = haystack + pos;
+ auto iEnd = haystack + size - nsize_1;
+
+ while (i < iEnd) {
+ // Boyer-Moore: match the last element in the needle
+ while (i[nsize_1] != lastNeedle) {
+ if (++i == iEnd) {
+ // not found
+ return npos;
+ }
+ }
+ // Here we know that the last char matches
+ // Continue in pedestrian mode
+ for (size_t j = 0;;) {
+ assert(j < nsize);
+ if (i[j] != needle[j]) {
+ // Not found, we can skip
+ // Compute the skip value lazily
+ if (skip == 0) {
+ skip = 1;
+ while (skip <= nsize_1 && needle[nsize_1 - skip] != lastNeedle) {
+ ++skip;
+ }
+ }
+ i += skip;
+ break;
+ }
+ // Check if done searching
+ if (++j == nsize) {
+ // Yay
+ return i - haystack;
+ }
+ }
+ }
+ return npos;
+}
+
+template <typename E, class T, class A, class S>
+inline typename basic_fbstring<E, T, A, S>::iterator
+basic_fbstring<E, T, A, S>::insertImplDiscr(
+ const_iterator i, size_type n, value_type c, std::true_type) {
+ Invariant checker(*this);
+
+ assert(i >= cbegin() && i <= cend());
+ const size_type pos = i - cbegin();
+
+ auto oldSize = size();
+ store_.expandNoinit(n, /* expGrowth = */ true);
+ auto b = begin();
+ fbstring_detail::podMove(b + pos, b + oldSize, b + pos + n);
+ fbstring_detail::podFill(b + pos, b + pos + n, c);
+
+ return b + pos;
+}
+
+template <typename E, class T, class A, class S>
+template <class InputIter>
+inline typename basic_fbstring<E, T, A, S>::iterator
+basic_fbstring<E, T, A, S>::insertImplDiscr(
+ const_iterator i, InputIter b, InputIter e, std::false_type) {
+ return insertImpl(
+ i, b, e, typename std::iterator_traits<InputIter>::iterator_category());
+}
+
+template <typename E, class T, class A, class S>
+template <class FwdIterator>
+inline typename basic_fbstring<E, T, A, S>::iterator
+basic_fbstring<E, T, A, S>::insertImpl(
+ const_iterator i,
+ FwdIterator s1,
+ FwdIterator s2,
+ std::forward_iterator_tag) {
+ Invariant checker(*this);
+
+ assert(i >= cbegin() && i <= cend());
+ const size_type pos = i - cbegin();
+ auto n = std::distance(s1, s2);
+ assert(n >= 0);
+
+ auto oldSize = size();
+ store_.expandNoinit(n, /* expGrowth = */ true);
+ auto b = begin();
+ fbstring_detail::podMove(b + pos, b + oldSize, b + pos + n);
+ std::copy(s1, s2, b + pos);
+
+ return b + pos;
+}
+
+template <typename E, class T, class A, class S>
+template <class InputIterator>
+inline typename basic_fbstring<E, T, A, S>::iterator
+basic_fbstring<E, T, A, S>::insertImpl(
+ const_iterator i,
+ InputIterator b,
+ InputIterator e,
+ std::input_iterator_tag) {
+ const auto pos = i - cbegin();
+ basic_fbstring temp(cbegin(), i);
+ for (; b != e; ++b) {
+ temp.push_back(*b);
+ }
+ temp.append(i, cend());
+ swap(temp);
+ return begin() + pos;
+}
+
+template <typename E, class T, class A, class S>
+inline basic_fbstring<E, T, A, S>& basic_fbstring<E, T, A, S>::replaceImplDiscr(
+ iterator i1,
+ iterator i2,
+ const value_type* s,
+ size_type n,
+ std::integral_constant<int, 2>) {
+ assert(i1 <= i2);
+ assert(begin() <= i1 && i1 <= end());
+ assert(begin() <= i2 && i2 <= end());
+ return replace(i1, i2, s, s + n);
+}
+
+template <typename E, class T, class A, class S>
+inline basic_fbstring<E, T, A, S>& basic_fbstring<E, T, A, S>::replaceImplDiscr(
+ iterator i1,
+ iterator i2,
+ size_type n2,
+ value_type c,
+ std::integral_constant<int, 1>) {
+ const size_type n1 = i2 - i1;
+ if (n1 > n2) {
+ std::fill(i1, i1 + n2, c);
+ erase(i1 + n2, i2);
+ } else {
+ std::fill(i1, i2, c);
+ insert(i2, n2 - n1, c);
+ }
+ assert(isSane());
+ return *this;
+}
+
+template <typename E, class T, class A, class S>
+template <class InputIter>
+inline basic_fbstring<E, T, A, S>& basic_fbstring<E, T, A, S>::replaceImplDiscr(
+ iterator i1,
+ iterator i2,
+ InputIter b,
+ InputIter e,
+ std::integral_constant<int, 0>) {
+ using Cat = typename std::iterator_traits<InputIter>::iterator_category;
+ replaceImpl(i1, i2, b, e, Cat());
+ return *this;
+}
+
+template <typename E, class T, class A, class S>
+template <class FwdIterator>
+inline bool basic_fbstring<E, T, A, S>::replaceAliased(
+ iterator i1, iterator i2, FwdIterator s1, FwdIterator s2, std::true_type) {
+ std::less_equal<const value_type*> le{};
+ const bool aliased = le(&*begin(), &*s1) && le(&*s1, &*end());
+ if (!aliased) {
+ return false;
+ }
+ // Aliased replace, copy to new string
+ basic_fbstring temp;
+ temp.reserve(size() - (i2 - i1) + std::distance(s1, s2));
+ temp.append(begin(), i1).append(s1, s2).append(i2, end());
+ swap(temp);
+ return true;
+}
+
+template <typename E, class T, class A, class S>
+template <class FwdIterator>
+inline void basic_fbstring<E, T, A, S>::replaceImpl(
+ iterator i1,
+ iterator i2,
+ FwdIterator s1,
+ FwdIterator s2,
+ std::forward_iterator_tag) {
+ Invariant checker(*this);
+
+ // Handle aliased replace
+ using Sel = std::integral_constant<
+ bool,
+ std::is_same<FwdIterator, iterator>::value ||
+ std::is_same<FwdIterator, const_iterator>::value>;
+ if (replaceAliased(i1, i2, s1, s2, Sel())) {
+ return;
+ }
+
+ auto const n1 = i2 - i1;
+ assert(n1 >= 0);
+ auto const n2 = std::distance(s1, s2);
+ assert(n2 >= 0);
+
+ if (n1 > n2) {
+ // shrinks
+ std::copy(s1, s2, i1);
+ erase(i1 + n2, i2);
+ } else {
+ // grows
+ s1 = fbstring_detail::copy_n(s1, n1, i1).first;
+ insert(i2, s1, s2);
+ }
+ assert(isSane());
+}
+
+template <typename E, class T, class A, class S>
+template <class InputIterator>
+inline void basic_fbstring<E, T, A, S>::replaceImpl(
+ iterator i1,
+ iterator i2,
+ InputIterator b,
+ InputIterator e,
+ std::input_iterator_tag) {
+ basic_fbstring temp(begin(), i1);
+ temp.append(b, e).append(i2, end());
+ swap(temp);
+}
+
+template <typename E, class T, class A, class S>
+inline typename basic_fbstring<E, T, A, S>::size_type
+basic_fbstring<E, T, A, S>::rfind(
+ const value_type* s, size_type pos, size_type n) const {
+ if (n > length()) {
+ return npos;
+ }
+ pos = std::min(pos, length() - n);
+ if (n == 0) {
+ return pos;
+ }
+
+ const_iterator i(begin() + pos);
+ for (;; --i) {
+ if (traits_type::eq(*i, *s) && traits_type::compare(&*i, s, n) == 0) {
+ return i - begin();
+ }
+ if (i == begin()) {
+ break;
+ }
+ }
+ return npos;
+}
+
+template <typename E, class T, class A, class S>
+inline typename basic_fbstring<E, T, A, S>::size_type
+basic_fbstring<E, T, A, S>::find_first_of(
+ const value_type* s, size_type pos, size_type n) const {
+ if (pos > length() || n == 0) {
+ return npos;
+ }
+ const_iterator i(begin() + pos), finish(end());
+ for (; i != finish; ++i) {
+ if (traits_type::find(s, n, *i) != 0) {
+ return i - begin();
+ }
+ }
+ return npos;
+}
+
+template <typename E, class T, class A, class S>
+inline typename basic_fbstring<E, T, A, S>::size_type
+basic_fbstring<E, T, A, S>::find_last_of(
+ const value_type* s, size_type pos, size_type n) const {
+ if (!empty() && n > 0) {
+ pos = std::min(pos, length() - 1);
+ const_iterator i(begin() + pos);
+ for (;; --i) {
+ if (traits_type::find(s, n, *i) != 0) {
+ return i - begin();
+ }
+ if (i == begin()) {
+ break;
+ }
+ }
+ }
+ return npos;
+}
+
+template <typename E, class T, class A, class S>
+inline typename basic_fbstring<E, T, A, S>::size_type
+basic_fbstring<E, T, A, S>::find_first_not_of(
+ const value_type* s, size_type pos, size_type n) const {
+ if (pos < length()) {
+ const_iterator i(begin() + pos), finish(end());
+ for (; i != finish; ++i) {
+ if (traits_type::find(s, n, *i) == 0) {
+ return i - begin();
+ }
+ }
+ }
+ return npos;
+}
+
+template <typename E, class T, class A, class S>
+inline typename basic_fbstring<E, T, A, S>::size_type
+basic_fbstring<E, T, A, S>::find_last_not_of(
+ const value_type* s, size_type pos, size_type n) const {
+ if (!this->empty()) {
+ pos = std::min(pos, size() - 1);
+ const_iterator i(begin() + pos);
+ for (;; --i) {
+ if (traits_type::find(s, n, *i) == 0) {
+ return i - begin();
+ }
+ if (i == begin()) {
+ break;
+ }
+ }
+ }
+ return npos;
+}
+
// non-member functions
// C++11 21.4.8.1/1
template <typename E, class T, class A, class S>
is.width(0);
break;
}
- if (isspace(got)) break;
+ if (isspace(got)) {
+ break;
+ }
str.push_back(got);
got = is.rdbuf()->snextc();
}
}
template <typename E1, class T, class A, class S>
-const typename basic_fbstring<E1, T, A, S>::size_type
-basic_fbstring<E1, T, A, S>::npos =
- static_cast<typename basic_fbstring<E1, T, A, S>::size_type>(-1);
+constexpr typename basic_fbstring<E1, T, A, S>::size_type
+ basic_fbstring<E1, T, A, S>::npos;
#ifndef _LIBSTDCXX_FBSTRING
// basic_string compatibility routines
#define FOLLY_FBSTRING_HASH1(T) \
template <> \
- struct hash< ::folly::basic_fbstring<T>> { \
+ struct hash< ::folly::basic_fbstring<T>> { \
size_t operator()(const ::folly::basic_fbstring<T>& s) const { \
return ::folly::hash::fnv32_buf(s.data(), s.size() * sizeof(T)); \
} \
projects / folly.git / commitdiff